JPH10278305A - Image forming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a recovery mechanism for an ink jet head employing a high viscosity quick dry ink. SOLUTION: The image forming system comprises means 14 for carrying a print medium 13 toward a print position and carrying out a printed medium 13 therefrom, a table 12 for mounting the medium carrying means 14, means 11 for driving the table 12 in the direction intersecting the carrying direction of the print medium 13, and means 26, 31 mounted on the table 12 for correcting the ink jetting state of an ink jet head 24. The table driving means 11 moves the table 12 between a print processing position where an image can be printed on the print medium 13 and a recovery processing position where the ink jet 24 can be recovered by the recovery means 26, 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for printing a desired image by discharging a liquid onto a print medium, and is particularly suitable for various types of print media produced in small quantities. .

[0002]

2. Description of the Related Art Characters representing the contents of optically recorded information and the like on the surface opposite to the data surface which is the signal recording surface of a disk-shaped optical disk such as a laser disk, a compact disk, or a mini disk, that is, on the label surface. Conventionally, image information is printed by a method such as screen printing or offset printing.

As an alternative to such a printing method for a print medium formed of resin or metal,
For example, an ink jet printer described in JP-A-64-38237 is known. In this ink jet printer, an ink jet head and a compact disk, which is a disk-shaped print medium, are moved along two directions orthogonal to each other, and a desired image is printed on the label surface of the compact disc. Things.

[0004]

When an image is printed on the surface of a print medium by a method such as screen printing or offset printing, a screen plate or an offset plate is required. It takes a lot of production days, and in particular, in the case of various types of print media produced in small quantities, there is a problem that the printing cost per print medium is high.

[0005] The ink jet printer disclosed in Japanese Patent Application Laid-Open No. 64-38237 can print directly on a print medium, so that the above-mentioned problems can be prevented. However, inks used for print media such as resins and metals that do not substantially penetrate the ink require faster drying and higher viscosity than inks used for print media such as paper. For this reason, clogging often occurs, which may result in poor printing. For this reason, in an ink jet printer that needs to use relatively quick-drying and high-viscosity ink, it is essential to incorporate a recovery processing mechanism that eliminates clogging of the ink jet head and realizes stable ink ejection.

However, in a conventional ink-jet printer, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-179761, a very complicated operation must be performed in order to perform the recovery process, which is necessary for the recovery process. In addition to an increase in time, the configuration of the apparatus for this purpose is complicated, and this is one of the factors that cause a decrease in operating efficiency.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus which can simplify a recovery mechanism for an ink jet head which requires the use of a relatively quick-drying and highly viscous ink.

[0008]

According to a first aspect of the present invention, there is provided an image forming apparatus for printing an image on a surface of a print medium using an ink jet head for discharging ink, wherein the print medium is printed. And a table on which the medium conveying means is mounted, and a table on which the medium conveying means is mounted, and a direction in which the medium is conveyed by the medium conveying means. A table driving means for moving in an intersecting direction, and a recovery means mounted on the table to make the ink ejection state of the ink jet head proper, wherein the table driving means prints an image on the print medium. And the ink jetting by the recovery means. In an image forming apparatus, characterized in that for moving the table and recovery possible recovery processing position of the head.

According to the present invention, when the table is at the print processing position, a predetermined image is printed by the ink jet head on the print medium carried into the print position by the medium carrying means, and is carried out of the print position by the medium carrying means. Is done.

[0010] When the ink jet head recovery processing becomes necessary, the table driving means is operated to move the table to the recovery processing position. Perform processing. Then, when this recovery processing is completed, the table driving means is operated to move the table again to the print processing position, and restart the print operation on the print medium.

According to a second aspect of the present invention, there is provided an image forming apparatus for printing an image on the surface of a print medium using an ink jet head for discharging ink from a discharge port, wherein an area occupied by the ink jet head is provided. And a capping member that receives the ink ejected from the discharge port while covering the discharge port surface where the discharge port opens, a capping member moving unit that moves the capping member in a direction facing the area, A table disposed between an area and the capping member, table driving means for moving the table in a direction intersecting with the moving direction of the capping member, and movement of the capping member and the table mounted on the table Orient the print media in the direction intersecting the print direction A medium transporting means for carrying in and carrying out the printed print medium from the printing position, and a wiping blade attached to the table for wiping the discharge port surface, wherein the table driving means comprises: The table is at a print processing position at which an image can be printed on a medium, a wiping position at which the wiping blade can wipe the discharge port surface, and a capping position at which the capping member can cover the discharge port surface. In the image forming apparatus.

According to the present invention, when the table is at the print processing position, a predetermined image is printed by the ink jet head on the print medium conveyed to the print position by the medium conveyance means, and is ejected from the print position by the medium conveyance means. Is done.

When the recovery process of the ink jet head becomes necessary, the table driving means is operated to move the table to the wiping position, and the discharge port surface is wiped by the wiping blade protruding from the table. Further, by operating the table driving means to move the table to the capping position, the ink jet head and the capping member are opposed to each other, and the ejection port surface of the ink jet head is covered with the capping member by the capping member moving means. In this state, preliminary ejection of ink is performed from the inkjet head. The above operation is repeated as necessary.

Then, when this recovery process is completed,
After the capping member is separated from the ink jet head by operating the capping member moving means, the table is moved to the print processing position again by operating the table driving means, and the printing operation on the print medium is resumed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an image forming apparatus according to a first aspect of the present invention, a recovery means covers ink discharged from a discharge port by covering a discharge port surface of a discharge port for discharging ink of an ink jet head. It may have a receiving capping member, and a wiping blade disposed between the capping member and the medium conveying means for wiping the discharge port surface. In this case, it is preferable to further include a capping member moving unit for moving the capping member in a direction facing the area occupied by the inkjet head.

In the image forming apparatus according to the first and second embodiments of the present invention, the image forming apparatus further includes blade moving means for moving the wiping blade between a work position where the discharge port surface can be wiped and a retracted position where the discharge port surface does not contact the discharge port surface. It may be something. In this case, it is preferable to further include a cleaning unit for cleaning the wiping blade at the retracted position.

Further, the apparatus may further include a medium carrying-in means for carrying the print medium into the medium carrying means, and a medium carrying-out means for carrying out the printed print medium from the medium carrying means.

Further, the discharge port may be formed in the ink jet head over the entire area in the width direction of the print medium orthogonal to the direction in which the print medium is transported by the medium transport means.

On the other hand, the ink jet head may have a discharge energy generating section for discharging ink from the discharge port. In this case, it is preferable that the discharge energy generation unit has an electrothermal converter that generates heat energy.

The print medium may be formed of a metal, resin, or the like, through which ink hardly penetrates, and an optical disk is particularly preferable.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which an image forming apparatus according to the present invention is applied to a system for printing on a label surface of a compact disc will be described in detail with reference to FIGS.

FIGS. 1 and 2 show the plan configuration of the print processing state and the recovery processing state in this embodiment, respectively, and FIG.
And FIG.

That is, on a table 12 which is reciprocally movable by a table driving cylinder 11 between a print processing position shown in FIG. 1 and a capping position shown in FIG. A transport conveyor 14 that transports the compact disc 13 in the direction in which the compact disk 13 moves is installed. The table 12 is provided on both sides of the conveyor 14 in the conveying direction with the table 12 interposed therebetween.
Conveyor 15 and carry-out conveyor 1 for transporting the compact disks 13 in parallel with the reciprocating direction of the
6 are provided.

The transport conveyor 14 has a pair of transport rollers 17 and 18 rotatably mounted on the table 12.
And an endless transport belt 19 wound around these transport rollers 17 and 18, and a stepping motor or the like connected to one transport roller (hereinafter, referred to as a drive roller) 17 and driving the same with high precision. And a transport motor 20. Further, between the table 12 and the other transport roller (hereinafter, referred to as a driven roller) 18, the driven roller 18 is urged in a direction away from the drive roller 17 to remove the slack of the transport belt 19. The tension adjusting means is not provided.

In the present embodiment, the feeding accuracy of the compact disc 13 is ensured with high accuracy, and the driving rotation of the driving roller 17 is transmitted to the conveying belt 19 by frictional force. The drive roller 17 is formed of rubber and the outer peripheral surface thereof is covered with a synthetic rubber having a high friction coefficient to secure a frictional force with the drive roller 17. However, as long as the feeding accuracy of the transport belt 19 can be ensured, it is of course possible to form the transport belt 19 with a metal or resin film other than the hard synthetic rubber as in the present embodiment.

Loading conveyor 1 with label surface facing up
5 compact disc 13 conveyed intermittently
Is transported to a carry-in position set on the upstream side of the transport conveyor 14 in the transport direction by suction by a carry-in transfer device 22 having an air chuck 21.

The printed compact disc 13 conveyed to the carry-out position set downstream of the carry conveyor 14 in the carrying direction is sucked by the carry-out transfer device 23 having the air chuck 21 and is carried out by the carry-out conveyor 16.
It is transferred above and sent out for the next process such as inspection and packaging.

A print position for printing a predetermined image on the compact disc 13 is set between the carry-in position and the carry-out position set on the conveyor 14.

Conveyor 1 at print processing position
Immediately above the print position set at the center of the ink jet head 4, an ink jet head 24 in which ejection ports (not shown) for ejecting ink are arranged over the entire area in the width direction (left and right directions in FIG. 1) of the conveyor belt 19 is directed downward. Is provided. The inkjet head 24 in the present embodiment is a full-line type bubble jet head having an electrothermal converter that generates thermal energy that causes film boiling of the ink, as a discharge energy generating unit used for discharging the ink. Yes, and can be replaced as needed.

While the compact disc 13 moves on the conveyor 14 and passes the printing position,
A predetermined image is printed on the label surface of the compact disc 13 by the ink discharged from the discharge port of the inkjet head 24.

At the capping position shown in FIG. 2 on the table 12, a capping member 26 for covering a discharge port surface 25 having a discharge port facing the ink jet head 24 is provided via a capping member elevating device 27. The retreat position close to the table 12 side and the discharge port surface 2
5 is provided so as to be able to move up and down at a capping position covering the same. The capping member 26 incorporates an ink absorber 28 formed of a porous material such as sponge or felt for holding ink. A seal ring 29 is attached to the contact surface of the capping member 26 so as to be elastically deformed against the discharge port surface 25 of the inkjet head 24.

Between the capping member 26 and the conveyor 14, while the table 12 moves from the print processing position to the capping position, ink droplets adhering to the discharge port surface 25 of the ink jet head 24 are removed. A wiping device 31 having a wiping blade 30 for wiping dust or the like is provided. The wiping device 31 according to the present embodiment includes a cleaning tank 32 installed on the table 12 for storing a cleaning liquid for cleaning the tip of the wiping blade 30, and a cleaning tank 32 installed above the cleaning tank 32. Tank 33 for storing unused cleaning liquid to be supplied to
A cleaning liquid supply pipe 34 connecting the cleaning liquid supply pipe 3 to the cleaning tank 32; an opening / closing valve 35 interposed in the cleaning liquid supply pipe 34 to open and close the cleaning liquid supply pipe 34; And a cleaning liquid discharge pipe 37 for discharging excess cleaning liquid in the cleaning tank 32 to the outside.

The base end of the wiping blade 30 is held between the blade holder 38 and the fixing plate 39. A swing shaft 40 protruding from the side of the blade holder 38 is pivotally supported on the table 12 so as to be rotatable.
The blade drive motor 41 connected to one end of the
The oscillating shaft 40 can be rotated by 180 degrees between a wiping position indicated by a solid line in FIG. 3 and a cleaning position (retreat position) indicated by a two-dot chain line. A suction passage 42 is formed in the blade holder 38 so as to open on the contact surface with the wiping blade 30 over the other end of the swing shaft 40. The cleaning liquid or ink impregnated in the wiping blade 30 is suctioned and discharged by a suction pump 44 connected via 43. Thereby, the wiping blade 3
The amount of the cleaning liquid remaining at zero is appropriately reduced, the ability to absorb ink, foreign matter, and the like is recovered and maintained, and the cleaning effect on the discharge port surface 25 of the inkjet head 24 is enhanced.

The wiping blade 30 can be made of a flexible polymer porous body. In this case, a type in which the volume change due to absorption of the ink mist is not remarkable, such as a polymer foam, and the volume does not change even when the ink is absorbed is preferable. For example, those using a foamed formal resin seem to be suitable.

When the apparatus of this embodiment is stopped, the ejection port surface 25 of the ink jet head 24 is covered with a capping member 26 to prevent drying of the ink in the ejection port and entry of foreign matter. When the printing operation is started from this state, after performing a preliminary ejection operation of the ink from the inkjet head 24 toward the ink absorber 28 of the capping member 26, the capping member elevating device 27 is driven to lower the capping member 26. ,
The table driving cylinder 11 is driven to move the table 12 from the capping position shown in FIG. 2 to the print processing position shown in FIG. At this time, the wiping blade 30 is at the retracted position shown by a two-dot chain line in FIG.
Avoid contact with

When the table 12 moves to the print processing position, the compact disc 1 on the carry-in conveyor 15
The compact disc 13 is transported by the loading transfer device 22 to the loading position on the transport conveyor 14 in a positioned state, and the compact disc 13 is transported to the printing position by the transport conveyor 14 and a predetermined image is formed by ink ejected from the inkjet head 24. Print Then, the sheet is unloaded from the unloading position onto the unloading conveyor 16 by the unloading transfer device 23.

When the recovery process is required, the wiping blade 30 is driven by driving the blade drive motor 41 as shown in FIG.
The wiping blade 30 is rotated by 180 degrees to the wiping position indicated by the solid line,
The remaining washing liquid is suctioned. Then, the table drive cylinder 11 is driven to move the table 12 from the print processing position shown in FIG. 1 to the capping position shown in FIG. 2. During the movement, the discharge port surface 25 of the inkjet head 24 is moved to the tip of the wiping blade 30. It is dispelled by the department. When the table 12 is moved to the capping position, the capping member elevating device 27 is driven to move the capping member 26 to the ejection port surface 2 of the inkjet head 24.
5 is received by the ink absorber 28 of the capping member 26. During this time, the blade drive motor 41 is driven to drive the wiping blade 3
3 is rotated 180 degrees to a cleaning position indicated by a two-dot chain line in FIG. 3, and the wiped blade 30 is cleaned by immersing the wiped blade 30 in the cleaning liquid in the cleaning tank 32.

In the above-described embodiment, the capping member 26 constituting a part of the recovery means is mounted on the table 12. However, the capping member 26 is provided separately from the table 12, thereby reducing the weight of the table 12 and moving the table 12 at high speed. It is also possible to improve production efficiency.

FIG. 5 shows a schematic structure of another embodiment according to the present invention, in which parts having the same functions as those in the previous embodiment are denoted by the same reference numerals, and duplicate description is omitted. And That is, the transport conveyor 14 and the wiping device 31 are mounted on the table 12, and the capping member 26 and the capping member lifting / lowering device (not shown) for lifting and lowering the same support the table driving cylinder 11, the carry-in conveyor 15, and the carry-out conveyor 16. It is installed on a base (not shown). That is, when the table driving cylinder 11 is operated to move the table 12 from the capping position shown in FIG. 5 to the print processing position, the state in which the table 12 and the transport conveyor 14 are interposed between the inkjet head 24 and the capping member 26 Become.

It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for discharging a liquid, particularly in an ink jet system. The present invention brings about an excellent effect in an ink jet apparatus of a system in which a change in the state of a liquid is caused by thermal energy. According to such a method, it is possible to achieve higher density and higher definition of the print.

The typical configuration and principle are described in, for example, US Pat. No. 4,723,129 and US Pat.
It is preferable to use the basic principle disclosed in Japanese Patent Application No. 0796. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or the flow path holding the liquid. Applying at least one drive signal to the electrothermal transducer that provides a rapid temperature rise exceeding nucleate boiling corresponding to the print information, thereby generating thermal energy in the electrothermal transducer and providing a thermal effect to the inkjet head. This is effective because film boiling occurs on the surface, and consequently, bubbles in the liquid corresponding to this drive signal can be formed one-to-one. By the growth and shrinkage of the bubble, the liquid is discharged through the discharge port to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of the liquid having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. In addition,
US Patent No. 4 of the invention relating to the rate of temperature rise of the heat acting surface
By employing the conditions described in the specification of Japanese Patent No. 313124, more excellent printing can be performed.

The structure of the ink jet head is a combination of a discharge port, a flow path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned respective specifications. In addition, the present invention includes a configuration using U.S. Pat. No. 4,558,333 or U.S. Pat. No. 4,459,600, which discloses a configuration in which a heat acting portion is arranged in a bent region. In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. JP-A-59-138461 which discloses a configuration corresponding to a discharge section
The effects of the present invention are effective even if the configuration is based on the above publication. That is, according to the present invention, printing can be performed reliably and efficiently regardless of the form of the inkjet head.

In addition, the provision of auxiliary auxiliary means for the ink jet head as a constitution of the ink jet apparatus of the present invention can further stabilize the effect of the present invention.
It is preferred. Specific examples thereof include a preheating means for performing heating using an electrothermal transducer, another heating element, or a combination thereof.

Further, as for the type and number of ink jet heads to be mounted, for example, in addition to the ink jet head provided with only one corresponding to a single color ink, it corresponds to a plurality of inks having different print colors and densities. A plurality may be provided. That is, for example, the print mode of the inkjet apparatus is not limited to the print mode of only the mainstream color such as black, but may be either an integrated inkjet head or a combination of a plurality of inkjet heads. The present invention is also very effective for an apparatus provided with at least one of the full-color print modes using mixed colors.

In addition, in the embodiment of the present invention described above, a material which solidifies at room temperature or lower and softens or liquefies at room temperature may be used. In general, the temperature is controlled within the range of not more than ° C. and the temperature is controlled so that the viscosity of the liquid is in a stable ejection range. In addition, in order to positively prevent the temperature rise due to thermal energy by using it as the energy of the state change from the solid state to the liquid state, or to prevent the evaporation of the liquid,
What solidifies in a standing state and liquefies by heating may be used. In any case, the liquid is liquefied by the application of the thermal energy according to the print signal, and is liquefied only by the application of the thermal energy, such as the one from which the liquid is ejected and the one which already starts to solidify when reaching the print medium. The present invention can be applied to the case of using a material having a property. The liquid in such a case is disclosed in JP-A-54-56847.
JP-A No. 60-71260 or JP-A-60-71260, in a state in which the porous sheet is held as a liquid or solid substance in a concave portion or a through-hole and faces the electrothermal converter. Is also good. In the present invention,
The most effective one for each of the above-mentioned liquids is to execute the above-mentioned film boiling method.

[0046]

According to the image forming apparatus of the present invention, the medium carrying means for carrying the print medium is mounted on the table,
Since the table is moved to a print processing position where an image can be printed on a print medium and a recovery processing position where the recovery of the inkjet head can be performed by the recovery unit so that the inkjet head and the recovery processing unit face each other. The print processing and the recovery processing can be switched at high speed with a simple configuration, and the production efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment in which an image forming apparatus according to the present invention is applied to printing of a compact disc, showing a state where a table is located at a print processing position.

FIG. 2 is a plan view showing a state where a table is located at a capping position in the embodiment shown in FIG. 1;

FIG. 3 is a conceptual diagram showing a schematic structure of a recovery processing unit in the embodiment shown in FIG.

FIG. 4 is a perspective view showing an appearance of a main part of a recovery processing unit in the embodiment shown in FIG.

FIG. 5 is a plan view of another embodiment of the image forming apparatus according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 table drive cylinder 12 table 13 compact disk 14 transport conveyor 15 carry-in conveyor 16 carry-out conveyor 17 carry roller (drive roller) 18 carry roller (driven roller) 19 carry belt 20 carry motor 21 air chuck 22 carry-in transfer device 23 carry-out Transfer device 24 Inkjet head 25 Discharge port surface 26 Capping member 27 Capping member elevating device 28 Ink absorber 29 Seal ring 30 Wiping blade 31 Wiping device 32 Cleaning tank 33 Spare tank 34 Cleaning liquid supply pipe 35 Opening / closing valve 36 Drain port 37 Cleaning liquid Discharge tube 38 Blade holder 39 Fixing plate 40 Swing shaft 41 Blade drive motor 42 Suction passage 43 Rotary joint 44 Suction pump

Claims (11)

[Claims] 1. An image forming apparatus for printing an image on a surface of a print medium using an ink jet head that discharges ink, wherein the print medium is carried toward a print position and printed from the print position. A medium carrying means for carrying out the print medium, a table on which the medium carrying means is mounted, a table driving means for moving the table in a direction intersecting a direction in which the medium is carried by the medium carrying means, and the table A recovery unit mounted on the inkjet head to make the ink ejection state of the ink jet head appropriate, wherein the table driving unit includes a print processing position at which an image can be printed on the print medium; To the recovery processing position where the inkjet head can be recovered An image forming apparatus characterized in that to move the serial table. 2. The ink jet head according to claim 1, wherein the recovery unit includes a capping member that covers an ejection port surface where the ejection port that ejects the ink of the inkjet head is open and receives the ink ejected from the ejection port. 2. The image forming apparatus according to claim 1, further comprising: a wiping blade disposed between the discharge port and the wiping unit for wiping the discharge port surface. 3. The image forming apparatus according to claim 1, further comprising a capping member moving unit configured to move the capping member in a direction facing a region occupied by the inkjet head. 4. An image forming apparatus for printing an image on the surface of a print medium using an ink jet head that discharges ink from a discharge port, wherein the discharge port faces an area occupied by the ink jet head, and the discharge port has an opening. A capping member that receives the ink ejected from the ejection port while covering the ejection port surface to be moved; a capping member moving unit that moves the capping member in a direction opposite to the area; and between the area and the capping member. A table to be disposed; table driving means for moving the table in a direction intersecting with the direction of movement of the capping member; mounted on the table; and a table driving means intersecting the direction of movement of the capping member and the table. The print medium is carried toward the print position and this print And a wiping blade attached to the table for wiping the discharge port surface, wherein the table drive unit prints an image on the print medium. The table is moved to a print processing position at which the table can be wiped, a wiping position at which the wiping blade can wipe the discharge port surface, and a capping position at which the capping member can cover the discharge port surface. An image forming apparatus, comprising: 5. The apparatus according to claim 2, further comprising blade moving means for moving said wiping blade between a work position where said discharge port surface can be wiped and a retracted position which does not contact said discharge port surface. 5. The image forming apparatus according to any one of 4. 6. The image forming apparatus according to claim 5, further comprising cleaning means for cleaning the wiping blade at the retracted position. 7. A medium carrying means for carrying the print medium into the medium carrying means, and a medium carrying means for carrying out the printed print medium from the medium carrying means. The image forming apparatus according to claim 1. 8. The ink jet head according to claim 1, wherein the discharge port is formed in an entire area in a width direction of the print medium orthogonal to a direction in which the print medium is transported by the medium transport unit. Items 1 to 7
The image forming apparatus according to any one of the above. 9. The image forming apparatus according to claim 1, wherein the ink jet head has a discharge energy generating section for discharging ink from the discharge port. 10. The image forming apparatus according to claim 9, wherein the discharge energy generation section has an electrothermal converter that generates heat energy. 11. The image forming apparatus according to claim 1, wherein said print medium is an optical disk.